Metal Slug on GBA no more

According to the latest issue of Famitsu, by way of DS-x2, four Metal Slug titles slated for released on the GBA have been cancelled. Metal Slug, Metal Slug 2, Metal Slug 3, and Metal Slug X have all been tossed to the garbage. No other information explaining why the titles have been cancelled is available. Could it have something to do with the upcoming release of Metal Slug Anthology?